Biological Control with Gratiana boliviana

Spread of Gratiana boliviana

Some biological control agents spread very rapidly to colonize new areas, whereas others disperse more slowly.  Gratiana boliviana spreads fairly slowly.  Research suggests that the beetle will spread from release sites at a rate of about one mile per year.  Thus, in order to speed up effective biological control of TSA, the beetle needs to be released at many different sites.  Eventually, the beetle will fill in gaps between release sites and occupy all areas of the state infested with TSA.